Burn-in method for surface emitting semiconductor laser device

Abstract

A burn-in method includes applying a stress current for applying thermal stress to a surface-emitting semiconductor laser, measuring an operation characteristic of the surface-emitting semiconductor laser to which the stress current is applied, and making a pass/fail decision on the surface-emitting semiconductor laser on the basis of the operation characteristic measured.

What is claimed is: 
     
       1. A burn-in method comprising:
 applying a stress current for applying thermal stress to a surface-emitting semiconductor laser, the stress current being applied for about 2 seconds and causing the surface-emitting semiconductor laser temperature to be around 600° C.; 
 measuring an operation characteristic of the surface-emitting semiconductor laser to which the stress current is applied, the operation characteristic being one of an electro-optic characteristic and an electric characteristic of the surface-emitting semiconductor laser; and 
 making a pass/fail decision on the surface-emitting semiconductor laser on the basis of the operation characteristic measured, 
 wherein the stress current is greater than a drive current which causes a thermal rollover and is less than another current that causes the surface-emitting semiconductor laser to fail due to overcurrent. 
 
     
     
       2. The burn-in method according to  claim 1 , wherein the surface-emitting semiconductor laser is placed at an environment temperature that is about a room temperature of 25° C. 
     
     
       3. The burn-in method according to  claim 1 , further comprising:
 attaching a wafer on which multiple surface emitting semiconductor lasers are formed to a support member at an environment temperature that is about a room temperature of 25° C.; and 
 applying the stress current to the multiple surface emitting semiconductor lasers and measuring operation characteristics of the multiple surface emitting semiconductor lasers. 
 
     
     
       4. The burn-in method according to  claim 3 , wherein each of the multiple surface emitting semiconductor lasers is subjected to the applying the stress current to the multiple surface emitting semiconductor lasers and is successively subjected to the measuring operation characteristics of the multiple surface emitting semiconductor lasers. 
     
     
       5. The burn-in method according to  claim 1 , further comprising:
 attaching multiple surface emitting semiconductor laser devices to a support member at an environment temperature that is about a room temperature of 25° C., each of the multiple surface emitting semiconductor laser devices including a single surface emitting semiconductor laser; and 
 applying the stress current to the multiple surface emitting semiconductor laser devices and measuring operation characteristics of the multiple surface emitting semiconductor laser devices. 
 
     
     
       6. The burn-in method according to  claim 1 , wherein the measuring the operation characteristic includes measuring an optical output characteristic of the surface emitting semiconductor laser while applying a measurement current to the surface emitting semiconductor laser. 
     
     
       7. The burn-in method according to  claim 1 , wherein:
 the measuring the operation characteristic includes measuring an operating voltage obtained while the stress current is applied to the surface emitting semiconductor laser; and 
 the making the pass/fail decision judging that the surface emitting semiconductor laser is normal when the operating voltage is lower than a threshold value and judging that the surface emitting semiconductor laser is faulty when the operating voltage is equal to or higher than the threshold value. 
 
     
     
       8. The burn-in method according to  claim 1 , wherein the operation characteristic is one of optical power and operation voltage of the surface-emitting semiconductor laser.